diff --git a/data/bad_seq.txt b/data/bad_seq.txt
new file mode 100644
index 0000000..5fba2e1
--- /dev/null
+++ b/data/bad_seq.txt
@@ -0,0 +1,4 @@
+>P_1|1|training
+CGCCUCCCACGCGGGAGACCCGGGUUCAAUUCCCGGCCAAU
+>P_21|training
+CCGGGUUCAAUUCCCGGCCACUGCACGUGGUUGUUUUUCAC
diff --git a/util/FileProcessing.py b/util/FileProcessing.py
index 5926a22..bc596c2 100644
--- a/util/FileProcessing.py
+++ b/util/FileProcessing.py
@@ -34,7 +34,7 @@ def __init__(self, file):
 
 
         else:
-            self.error_msg = 'File format error.'
+            pass
 
     def read_fasta(self, file):
         """
@@ -55,6 +55,8 @@ def read_fasta(self, file):
             header, sequence = array[0].split()[0], re.sub('[^ACDEFGHIKLMNPQRSTUVWY-]', '-', ''.join(array[1:]).upper())
             header_array = header.split('|')
             name = header_array[0]
+            if len(header_array) != 3:
+                return [], None, f"fasta file parsing failed at \"{header}\""
             label = header_array[1] if len(header_array) >= 2 else '0'
             label_train = header_array[2] if len(header_array) >= 3 else 'training'
             fasta_sequences.append([name, sequence, label, label_train])